Preliminary Investigation: Oral Adhesive Patches for the Delivery of Fluoride

Fluoride treatments have been shown to be valuable for the prevention of several types of dental disease. This study investigates a new approach to applying fluoride to dental tissues. Objectives: There are two specific aims of this study: 1) develop drug delivery patches that will adhere sufficiently to the surfaces of teeth and 2) develop patches that will increase the fluoride content of the enamel under the patches. Methods: Collagen (gelatin: bovine type A) was used in this study. This polymer with equal parts water was formulated with the addition of 4% sodium fluoride and then formed under heat into a viscous gel. Several types of patches were developed - the ones used in this study remained on the teeth for the three day test period. Extracted teeth were prepared with phosphoric acid etchant on the facial surfaces where patches would later be applied. The collagen gel was applied, while still viscous, to extracted teeth divided into three groups: one application, two applications, and three applications. The amount of diffusion of fluoride into the dental enamel was determined using scanning electron microscopy with energy dispersive x-ray analysis. The composition of the enamel where the patch was present was compared to areas where the patch was not present (buccal vs. lingual surfaces). Results: The single, double, and triple application groups showed 38%, 1224%, and 4303% increases in fluorine after the patch treatments. ANOVA showed that there were statistically significant differences between the double and triple application treatment groups and their respective controls (p≤0.05), but not between the single application group and it's control (p=0.29). Conclusion: The use of fluorine containing gel patches increased fluorine levels for the two and three application treatments compared to the controls. Increasing the number of applications increased the fluorine levels. Partially funded by NIDCR T35 DE07057.